Suarez's lawyer Alejandro Balbi, who is also a Uruguay FA board member, has travelled to Rio de Janeiro to defend the Liverpool striker and has suggested there is a conspiracy against him led by England and Italy.

The case is expected to be dealt with swiftly and an outcome announced well ahead of Uruguay's match with Colombia on Saturday. Suarez's sponsors including adidas are keeping a close eye on the outcome.

The video evidence appears damning and one senior FIFA official with experience of disciplinary cases, who asked to remain anonymous, believes the biting should be judged to be at least as serious as spitting, which carries a minimum six-game ban - something which would see Suarez's World Cup brought to an abrupt end.

The independent disciplinary panel, chaired by Swiss lawyer Claudio Sulser, has a range of sanctions available up to a 24-match ban or a two-year suspension from all football. A worldwide ban would impact on his playing for Liverpool but there is no precedent for such a sanction happening.

It is not certain Suarez's previous bans - 10 games for biting Chelsea's Branislav Ivanovic and seven matches for biting PSV Eindhoven's Otman Bakkal - will be taken into consideration, but the panel have that power.

A FIFA spokeswoman said: "They can take in all elements they deem necessary."

Suarez was not due to appear in person at the disciplinary hearing, but his lawyer and Uruguay FA president Wilmar Valdez will present his defence. Valdez told the Associated Press shortly after midnight local time that the hearing would continue on Thursday morning.

There are also reports that they will claim pictures of teeth-marks on Chiellini's shoulder were digitally altered. Suarez's lawyer suggested there was a conspiracy against his client.

Balbi told Uruguayan radio: "We don't have any doubts that this has happened because it's Suarez involved and secondly because Italy have been eliminated. There's a lot of pressure from England and Italy.

"There is a possibility that they ban him, because there are precedents, but we're convinced that it was an absolutely casual play, because if Chiellini can show a scratch on one shoulder, Suarez can show a bruised and an almost-closed eye.

"If every player starts showing the injuries he suffers and they open inquiries for them everything will be way too complicated in the future. We're going to use all the arguments possible so that Luis gets out in the best possible way."

Suarez and the Uruguayan FA had been given until 5pm local time (9pm BST) on Wednesday to provide evidence to support his case after the incident in the latter stages of the Group D encounter in Natal, which Uruguay won 1-0 to secure a last-16 clash against Colombia.

Suarez defended himself on Uruguayan television after the flashpoint, saying: "These situations happen on the pitch, we were both just inside the area, he struck me in the chest with his shoulder and he hit me in the eye as well."

Chiellini, however, insists that Suarez knew exactly what he was doing and was dismayed that he was not sent off for his apparent actions.

FIFA's disciplinary committee met immediately after the match and announced in the early hours of Wednesday that Suarez has been charged with misconduct.

Suarez is sponsored by adidas who, following his previous biting incident with Ivanovic, reminded the striker of his responsibilities. Executives from the sportswear manufacturer met in Rio to discuss the latest incident on Wednesday.

An adidas spokesperson said: "adidas is aware of the issue involving Luis Suarez. We await FIFA's full investigation into this matter and will respond accordingly.''

Uruguay captain Diego Lugano defended Suarez at a press conference in Natal, insisting he had the support of all his team-mates.

"The pictures don't show anything. They show an approximation. I find it funny the importance given to an isolated incident when no one pays attention to incidents which endanger the health of players," he said.

"Luis has charisma and he creates an advantage. An opponent tries to take it away, of course - that's as old as the game itself."